Orthopedic brace



March 24, 1953 R. ANDERSN' 2,632,442

' oRTHoPEDIc BRACE:

original Filed Apri1 11, 1944 2 SHEETS- SHEET 1 f3: :wy/2

mvlamoR fqyer'/rdanson ATTORNEYS March 24, 1953 R. ANDERSON 2,632,442

ORTHOPEDIC BRACE original Filed :April 11, 1944v 2 SHEETS- SHEET 2Evol-UTBON 4o 'or- Aca-roma lNoun-los sumas; wool aaa awiaav aso-m-laaswvu'sn'nw INVENTOR Q Y /r'ayer ndern/7 5'?. ATToRNEYs Patented Mar. 24,`1953 Y Roger Anderson, Seattle, Wash.

Original application Aprilv 11, 1944, ISerial No.

503,472.Y Divided and this application November 23, 1949, Serial No.129,068

(Cl. 12S-90) 7 Claims.

While the conventional plaster of Paris cast is useful in providingvaluable therapeutic results, it has many and recognized shortcomings.For example, the cast is characterized by excessive weight, its settingperiod to obtain maximum strength is long, it remains damp for longperiods and thus often provides adverse condi'- tions from a therapeuticstandpoint, it isdense, and to a greater degree when wet, to electricalrays, and it is highly absorbent to liquids including body secretions,water and airborne moisture. The absorbent characteristics of theplaster cast are not only favorable for germ incubation but the strengthof the cast is progressively lost depending upon the` amount ofsecretions, water and moisture to which the cast is exposed. Thesedisadvantages and others have provided a long feltne'ed in the art toprovide an entirely' new type of cast or splint'.

i The objects of the present application are substantially the same asthose of my Patent No.

2,489,252 of which the present application isa.

division and which objects are therein set forth. The invention of thepresent application differs from those ofA my said' patent in that theclaims of the present application are drawn to the completed orthopedicbrace as distinguished from.

the process of making the same.

It is further the object of the inventionto form a waterproof,relatively rigid unyielding and inelastic cast or splint which will.possess. a`

maximum strength combined. with.y a minimum weight.

In the present inventionA I provide aipl'astic fabrication which is verysimilar to the. touch and in, appearance to knitted yarn, as sweatermaterial or stockinette and preferably provide` the same in the form ofaA tubing or a form tting member or in strips of suitable width andthicknessso that suchmaterial may be properly fitted or wrapped about oradjacent an injured member and may be thereafter set-up to form a castor splint.

It is a further object of. my inventionV toy provide a cast membercharacterized in. a. substantial maintaining of the structural form 'of'the tained in the completed cast to form a truss-` like structure in thecompleted cast.

It is a further object of the invention to provide a cast which may bereadily cut or severed, mechanically, chemically, or both mechanicallyand chemically, for removal, extension, joining, local adjustment, orretting and a cast whichA after severance (or which may require repairfor any other reason) may be readily repaired: or reenforced withoutloss of, but usually with increased structural strength.

It is a` further object of the invention tor provide a practical plasticcast which will bey unaffected by moisture, as body secretions, wateror. air-borne moisture transparent to electrical rays, such as X-rays,or ultra-violet treating rays, and which may be of an open meshstructure so that the cast will facilitatetreatments, suchV as of thecast or the injured members by liquids of various natures.

It is a further object of the` invention to provide an open Weave meshfabric as the starting material wherein by the brousor filamentcharacter and open Weave thereof, the wetting characteristics of themateriali are enhanced. Because of the use of my treating solutionhaving limited dissolving properties, I a-ml able to' use an exceedinglyopen weave fabric without damagel to such fabric, a fabric havingexceptional wetting properties, and a fabricl having theV de siredthickness and a minimum weight-thus providing' a completed cast ofminimum weight and maximum strength.

It is'a further object of the invention to provide a cast-formingmaterial' preferably' having inert threads therein which will aid incontrol of the shrinkage characteristics during forming` myl completedcast.

The above mentioned general objects of my invention, together withothers inherent in the same, are attained by and illustrated in thestructures illustratedv in the following drawings, the

` form ofl fabrication employing therein, in addi- 3 tion to theplastic, an inert thread or yarn;

Fig. is a view of the fabrication of Fig. 4 after final treatment;

Fig. 6 is a fragmentary view with portions shown in section and portionsin elevation of a cast of my invention applied about a portion of thehuman body;

Fig. 7 is an enlarged fragmentary View of parts shown in section in Fig.6;

Fig. 8 is a view similar to Fig. 6 except that the outer layer of thecast is provided by a tubular member instead of a bandage;

Fig. 9 is a sectional view taken substantially on broken line 9-9 ofFig. 8;

Fig. 10 is a fragmentary view and with portions shown in elevation andportions shown in section to illustrate the use of padding means betweena sore spot or bony prominence, as an elbow, and a cast of my invention;

' Fig. 11 is a fragmentary view with portions shown in elevation andportions shown in section to illustrate a means of applying a solvent toremove portions, as a regular or irregular shaped hole, of a completedcast of my invention;

Fig. 12 is a fragmentary view with portions shown in elevation andportions shown in section of a completed cast of my invention in whichan opening has been provided and the cast then repaired;

Fig. 13 is a view similar to Fig. 11 except that the nature of theopening to be provided in the cast is a long narrow slot such as may beemployed in severing and removing the cast;

Fig. 14 is a view with parts shown in section and parts shown inelevation of a device which may be employed in applying treatingsolution of my invention to the fabrication of my invention; and

Fig. 15 is a chart comparing the saturation .A

values of a treating solution employed in my invention with thepercentage of acetone employed in the said solution.

Plastic employed I employ a plastic which has the followingcharacteristics: It is soluble in the treating solution employed (therelative extent being considered under the title Treating solution), itis relatively inelastic, and it is capable of being formed into piecesof hair-like dimension in section and preferably as a ber or threadlikefilament so that a yarn or thread may be provided from the same. Typicalexamples of such plastics are:

A. The cellulosic plastics 1. Cellulose esters:

a. Cellulose nitrate; R and R.=NO2 b. Cellulose acetate; R and R.=OC`CH3c. Cellulose acetate propionate;

R=OCCH3; R=OCC2H5 d. Cellulose acetate butyrate;

R=OCCH3; R=OCC`3II7 2. Cellulose ethers:

a. Ethyl cellulose: R and R=C2H5 volved.

B. Polystyrene plastics [-CH-ClhsHs n C. Vinyl ester plastics:

l. Polyvinyl acetate (The above chemical formulas are the conventionalrepresentations of the plastics in- I-Iowever, commercial furnishedplastics are not completely esteried as might be indicated by thechemical formulas.)

Form of materials The various individual fibers or laments of theplastics mentioned in the foregoing paragraph are preferably woven intoyarns, such as standard yarns of 150 denier weight. It is to beunderstood that the foregoing figure of denier Weight is not alimitation of this invention but is merely an example of a yarn whichmay be employed and which is at the same time a standard yarn.Preferably more than one piece of yarn is employed and as a practicalexample I have employed twelve individual pieces of yarn, each of 150ydenier weight and employed them as a unit in the knitting process.

From the knitting process I preferably obtain, for cast formingpurposes, a stretchable and relatively thick fabrication. Thus the typeof stitch to be employed in the knitting machine preferably should beone which provides a relatively stretchable fabrication and at the sametime the tension on the threads preferably should be relatively loose.As typical examples of various types of stitches which have beenemployed in the knitting of the fabrication employed in my invention, Ihave used the following stitches: cuff, link and link, full cardigan,full cardigan with rack, tubular and stockinette.

While the yarn employed in making the material into a stretchable andrelatively thick knitted fabrication may be solely a plastic, I preferto employ an inert material in each unit of yarn employed in theknitting process to control shrinkage. kThis material will be inert tothe treating solution employed (treating solutions are hereinafterspecifically considered) and if the treating solution employs thereinacetone then the inert material (that is inert so far as acetone isconcerned) may be cotton, regenerated rayon, glass, metal, nylon, etc.An example of an inert thread employed in the fabrication of myinvention is shown in Figs. 4 and 5 of the drawings. In such figures aplurality of plastic threads or yarns are disposed alongside andadjacent inert threads, as an inert thread I0. In the event that aninert thread is employed, it will control adverse shrinkage in theultimate overall size of the cast.

A theoretical explanation of the operation of the inert thread means isillustrated in Figs. 4

J and 5.` Fig. 4: illustrates a. fragment of the fabrication 26 beforetreatment and Fig. 5.- illustratesY the same after treatment. Thus the.thicknessA of the fabrication, as dimension I2 of Fig. 5v appears tol bereduced below thickness I3 of Fig. 4 butr the length I4 of both figures(a length or width dimension of the final cast) remains substantiallyconstant. The inert thread meansl by providing the thick material ofFig. 4 with excess material therein, permits theV materiali` to reduceits thickness and preserves the length dimension at right anglesthereto'.V

Fig. 1 illustrates the fabrication 26 beforetreatment. Fig. 2illustrates the same'after pretreatment in accordance with thepretreating technic discussed under Pretreating of the cast-formingmaterial, described hereinafter, and Fig. 3 illustrates thesame afterfinal treatment. The threads or yarn of the fabrication as woven (Fig.l) appear thicker in section and have more fnap or fuzz. Afterpretreating as shown in Fig. 2, the loops have an apparent vgreaterwidth asv dimension. I5 of Fig. 2 compared to` dimension I6 of Fig. 1.`Then after final treatment to provide a rigid supporting. means asa castthe dimension I1 of Fig. 3 is reduced over the comparable dimension I5of Fig. 2'. However, the dimension. I8 of both Figs.. 2 and. 3 issubstantially constant so the shrinkage of a. cast tending to reduce itssize is substantially eliminated.

The fabrication is preferably provided` in strips whichrnay be ofvarious widths. Theexact width of the material will be determined. bythe type of arti-cle which is to be made. In other words, the narrowerthe strip the easier itwill be to conform the strip about an irregularshaped object and at the same time the wider the strip the faster the`material maybe applied'. Thus for practical purposes I have employedstrips varying in Width from two to ten inches and of a length forconvenient handling.

Another form of: fabrication which I. have employed. in my invention isknitted. tubi-ng or material knitted substantially to the shape. of aparticular member, as a trunk', leg, etc., such. as a stocking. l

Other forms of fabrications will include Woven material, mattedmaterial, intertwined. material or intermeshed material. The means forholding the fabrication together so the same may be handled as a.L unitmay be the cross threads of a weave or knit, the entangled threads ofmatted, intertwined or intermeshed material, or mechanical means asWeld-like means, adhesive means, sewing, porous flexible containers', orthe like.

ited solubilitycharacteristics herein dened, were employed. Thus thestructures-or fabrications within theA scope of this` invention willalso` in-v clude (so long as the cross section of plastic employed iswithin the present teachings and regardlessof Whether a solid memberofplastic, ahollow member of plastic, or amember coated withr a plastic isemployed). threads-long or short, tubeslong or short, andv othergeometric solids, as beads, flat solids, etc. In the event that piecesof short length are employed they may be fabricated to be handled as aunit by employing them within-a porous flexible container' asa bag'.Also,k

flat solids may be secured together, much like shingles or sh scales,merely at one end. Also, if

an inert thread is selectively coated at longitudinally spacedlocations, the flexibility of the`V uncoated portions may be utilized.In thev description and the claims the Word fabrication is so used andshall have such meaning unless the contextrequ-ires a different meaning.

Pretreating of the cast-forming. material Preferably the fabricationpreviouslyv described is. pretreated before application about aninjured.

member so that the subsequent shrinkage characteristic of the materialupon final. treatmentl is controlled or eliminated. The most practicaltechnic for pretreating, I have discovered, com,-`

v full apparatus is illustrated and described in my The requisitecharacteristic of the fabrication is that it must comprise a pluralityof' pieces wherein the plastic employed is of filament or threadlikedimension in section and the` pieces are interoonnected to provide aunit or fabrication. The structures of my earlier mentioned patent` andpatentl application have a dimension in section of more than onethirty-second of an inch. In such instan-ces the size and dimension ofthe plastic: permitted the use of normal solvents, as acetone, Withoutexcess dissolving. In the pres'- ent invention I employ plastics havinga dimension of less than one thirty-second of an inch and which may betermed of thre'adlike dimension in section.y Because of their dimensionthey would be dissolved, lose shape, take too long. to dryl or set, oradverse amounts of gelatinousv matters would be formed'. if normalsolvents, as'v distinguished from treating solutions; having the lim--said Patent No. 2,489,252, of which the present application is adivision. The pretreating process may employ a liquid treatment, a heattreatment, or a combination of the two may be employed but preferably aliquid treatment in whole or in part is employed asa more uniformtreatment, cross-sectionally considered of the plastic, seems to result.y

If a heat treatment is employed, the temperature of the heat treatingfluid may be between 350 F. and 425 F. and for a period of 30 to 10second`s. A preferable temperature and time pe-A riod is about 375 F'.and for a period of approximately 25 seconds. VAs discussed underTreating solution, the saturation value of the pretreating solutionshould be below75.

I desire' to point out that in the technic of applying casts, control ofthe subsequent shrinkagey during setting of the cast is highlydesirable. In many cases itis desirableA that there shall be noshrinkagev of the cast and in other cases variations in the degree ofshrinkage are desirable for the utmost therapeutic results dependingupon` the nature' of the injury involvedv and/or the nature of thetreatment desired. For example, a cast may be applied about a recentlyamputated stump where the conditions are such that the surgeon desirespressure to reduce the swelling. In such cases the shrinkage duringsetting may be had so that pressure is applied to the swollen area. Alsoin such a type of case, a cast will have an increasingly greater litorconformation upon the gradual decrease of the swelling. A furtheradvantage from applying myv cast in such a case is that a temporaryartificial limb may be readilyV securedV to the cast and the patientwill be prompt-V lyl ambulatory. Also a cast maybe applied about aninjured limb shortly after the fracture and before considerable swellinghas set in and in suchl cases a minimum of. shrinkage of the cast in thesetting-up: process may be desired to allow for Any suitable apparatusmayY the anticipated subsequent swelling. Also a cast may be appliedabout very bony prominences and Where minimum swelling may be expected.

The technic of the use of casts varies with the individual case and theoperator and it is not my intention to indicate a method of treatmentbut merely to indicate some examples showing possible uses ofcontrolling the shrinkage characteristics of the cast during setting.

Treating solution A prime consideration in my invention is that thetreating solution shall be of a character to become saturated at a verylow concentration with the plastic employed and/or have the capacitybelow a predetermined maximum to react with the plastic employed eventhough the treating solution is liberally applied and an excess ispresent. This eliminates any necessity for a critical technic. Suchtreating solution may be a solvent for the plastic employed, such asethyl acetate; a solvent for such plastic combined with a diluent, asacetone and petroleum ether; two or more non-solvents for such plasticwhich in combination act as a solvent, as chloroform and ethyl alcohol;or any of the foregoing which have been first saturated by such plastic.

In the event that my invention is to be employed in connection with themedical and surgical fields in providing casts or splints then thetreating solution should be relatively volatile to provide for rapidsetting of the cast or splint and rapid drying of solution, should notbe harmful or irritating to the skin or exposed flesh or sores, if any,should not be toxic, and should not have an undesirable odor.

In order to determine the amount of a particular plastic required tosaturate a particular treating solution (hereinafter termed saturationvalue of a treating solution), I employed one hundred cc. of thesolution being tested and placed therein in finely comminuted form anexcess of the plastic to be employed in connection with the particulartreating solution and allowed the same to stand in a closed vessel for asubstantial period of time to insure complete saturation of the treatingsolution by the plastic. While the treating solution and the plastic mayonly be in association with one another for a matter of minutes inactual use in my invention, nevertheless, for test purposes I permittedthe treating solution and the plastic to stand in a closed vessel fortwenty-four hours to obtain results capable of being duplicated as tosaturation values. In View of the fact that an excess of plastic wasemployed to insure that the solubility characteristics of the treatingsolution would be fully satisfied some undissolved plastic and usuallysome gelatinous material were present. Then the liquid was passedthrough a filter paper so that only dissolved plastic would be presentin the liquid ltrate. Thereafter a measured amount of liquid filtratewas evaporated to dryness and the residue weighed.

With such technic for determining the saturation values of treatingsolutions formed of various ingredients and a specific example of eachcombination (and to compare the same to the saturation value of pureacetonewith acetone less than enough plastic to leave undissolved pieceswas employed so filtering was not needed) in connection with a typicalcommercial cellulose acetate yarn (at a room temperature of 8 about 70F.) the following results were observed:

Millliugrams of Composition ce OSO ace" Tieatmg Solution (by volume)trtapiglgglc.

tion

Percent Acetone 100 over 100, 000.00 Acetone 68 35 0 Petroleum ether(-60 C.) 32

44 68 gg 32. 5 34. 5 Methyl formate 70 26 3 Petroleum ether (35-60 C.)30 Methyl formate 60 Petroleum ether, 37%7 40 18. 3 Methanol, 2%% Methylformate. 66 71 3 Ethyl ether 34 Chloroiorm 99% 49 5 Ethyl alcohol Thestriking contrast of the low saturation values of the various treatingsolutions, set forth by way of example in the previous table, to theextremely high saturation value of acetone is obviously apparent. Thiscontrast will be helpful in understanding a possible theory involved inmy invention. However, in setting forth such a table, it is to beexpressly understood that the invention is not limited to the saturationvalues set forth in said table by way of example and the limits of theinvention will be hereinafter dened.

Also, in the table it will be apparent to those skilled in the art thatexamples of a solvent and a diluent therefore are involved in some ofthe treating solutions. For example, acetone is a solvent for celluloseacetate and petroleum ether is a diluent for acetone. However, theacetone and the diluent obviously do not function in direct relation tothe amount thereof present as the treating solution containingapproximately two-thirds acetone and one-third petroleum ether (byvolume) has a saturation value of 35 milligrams rather than two-thirdsof one hundred thousand milligrams.

containing acetone has a saturation value of 2690 milligrams per loo cc.of treating solution. Thus, the saturation values increase very rapidlyin comparison to the percentage of acetone included in the treatingsolution after a percentage such as 86% of acetone is reached. Thepercentage of acetone for obtaining any desired value of saturation fora treating solution comprising acetone and petroleum ether is believedobvious in view of said chart.

In view of the fact that those skilled in this art can readily prepare asaturation chart for any of the treating solutions which I havedisclosed, I have deemedk it unnecessary to here set forth a chart foreach treating solution. However, after a saturation chart is obtainedfor the treating solutionV embodying the technic which I have .9hereinbefore disclosed, then a treating solution having Lthepropersaturation value may be Areadily obtained for `a .given plastic and.employed vin my invention. Many of thesattuation .charts ier thetreating solutions whichIhave disclosed will follow generally the curvedisclosed in Fig. 15. However, many of the treating solutions of thisinvention will have saturation value curves which are very dissimilar tothe curve'represented in Fig. l`5. In connection with a treatingsolution comprising chloroform and ethyl alcohol, I may employ asolution wherein a very small amount of chloroform is present and a verylarge amount of ethyl alcohol is present and at the same time I may-employ a treating solution wherein a large amount -of chloroform and avery small amount of ethyl alcohol are present.

Another type of treatingsolution which may be employed in the inventionincludes solutions which have 'been previously treated Awith the plasticinvolved. For example any of the solutions mentioned in the said tablemay be treated by and even up to saturation vby .the plastic to beemployed and even after :substantially com-plete saturation they areoperable in my invention as treating solutions.

.Other types of treating solutions described in said table will includea solvent as ethyl .acetate or a combination of non-solvents in and ofthemselves which Vfunctionin combination as a solvent, aschloroformandethyl alcohol.

A possible theoretical explanation which `may be involved inthe actionofmy treating solutions is that one liquid, as rethyl alcohol, mayfunction as a disperser and another, as chloroform, may function as aswelling agent. Thus the chloroform may function to swell the plastic soportions will slurf-off and/ or be made available to be acted upon Abythe disperser. One ofthe facts which can be explained `by this `theoryis 'that solutions containing a large amount of chloroform and a smallamount of ethyl alcohol give limited solubility characteristics and atthe same time solutions containing a .small amount of chloroform and alarge amount of ethyl alcohol give similar results. Thus by eithercontrolling the swelling action or by controlling the dispersing action,limited solubility may be obtained. The action to which I have referredas a swelling action may be appropriately referred to as merely a stageof or an action occurring in dissolving. As to treating solutionscontaining agents, as acetone, it appears that the swelling action, ifpresent, and the dissolving action are brought about :by the same agent,acetone, ywhich seems to give credence to the theory that swellingis .astage of dissolving. However, despite the theory involved, myexperiments have demonstrated the utility of treating solutions havinglow saturation values.

'Ilrus my investigation indicates that it is necessary to employIatreating solution having a low saturation value for the plasticemployed and/or a :treating solution having a capacity below apredetermined maximum to react with the plastic employed and .thus`provide the necessary settingup action. Unless such low saturationvalue of this invention (as distinguished from 'a higher saturationvalue) is provided in the treating solution, there is a destruction ofthe fabrication and its structural form to an adverse degree, andformation vof an adverse amount of gelatinous material-these result inprolonged setting and drying time anda thin and weakened cast.

While I. am unable Aat this time to positively,

state the theoretical reasons Vfor the phenomenon as .to why `treatingsolutionshaving low saturation values are operable in my invention, onepossible explanation is that their capacity to dissolve plastic issatisfied before the occurrence of any substantial 'destruction of thestructure of the fabrication and that the dissolved plastic is sodispersed -or distributed that substantial quantit-ies of .a gelati-nousmass are not formed. Also the preferably employed highly volatiletreating solutions limit the time for the interaction between thetreating solution andthe plastic so that where said preferable solutionsare employed a minimum dissolving of the plastic takes place.` Also, apossible feature which may be involved in the theoretical explanation isthat there .is a capillary attraction between the Various hair-likefibers or nlaments .making up the various pieces of yarn or thread orYfabrica-tion and the treating solution so that in the time involved inAthe :reaction period, the major action is between the treating.solution which first wetted the plastic andthe .plastic itself and theexcess Vor subsequent applications of treating solution do not bringabout excessive dissolving of the plastic.

.A .possible theoretical reason .as to why` substantially saturated orpartially saturated solutions will .be l.operable in .the invention isthat of migration 'or exchange. Even though the treating solution issubstantially saturated with the plastic involved, it appears that thereis an expelling of the plastic which `saturated the solution and asimultaneous dissolvingof the plastic to .be treated so that bymigration or exchange in the treatingsolution between .the plasticinitially used to `saturate the solution and the plastic being treated,.the [plastic being treated is properly treated so ,it will subsequentlyset-up to provide a practical cast and without adverse destruction ofthe fabrication.

The setting-up action of my cast involves more than mere evaporation ofan extremely dilute cement or adhesive. I have taken a saturatedtreating .solution of the character above discussed and applied the sameto a material to which the solution is inert, as cotton, and evaporatedall liquid. Instead of iin-ding, as might be expected some residueencrusting or hardening the cotton, the cotton appeared to be the sameas it was before the treatment. There was such a small amount of residuethat its presence was diflicult to detect by the physical appearance orthe feel of the cotton. In contrast, the same treating solution whenapplied to a plastic 'fabrication provides a rigid structure. Thus thephenomenon of the setting-up action of a cast of my invention includesunexpected factors and cannot be explained as being merely the providingof a limited amount of cement in solution'and then evaporating theliquid.

-It appears that the minimumsaturation value of the treating solutionsor their apparent capacity to dissolve additional plastic may besubstantially zero and such treating solutions will be highly useful inmy invention. As to the maximum saturation value for treating solutionsWhich may be employed in the invention, I have found for optimumcommercial results in providing casts or splints that lthe same shouldbe not more than 100 milligrams of plastic per 100 cc. of treatingsolution calculated at '70 F. It has been found that any lgreatersaturation value than 100 milligrams of plastic per 1.00 cc. of treatingsolution is not necessary and limits latitude of technic in that carefulhandling is required `to prevent destruction of the structural for-m ofthe plastic fabrication, Thus in my tests I have purposely employedtreating solutions having saturation values of not over '75 milligramsof plastic per 100 cc. of treating solution as I obtain the desiredstrength with the greatest latitude in technic of application. On theother hand, I have found that with careful technic the saturation valuemay be as high as 300 milligrams of plastic per 100 cc. of treatingsolution and still useful results will `be obtained. Also where theplastic fabrication has been pretreated, as has been discussed undertitle Pretreating of the cast-forming material, the treating solution tobe employed may have a higher saturation value than when non-pretreatedmaterial is employed. For example, the range of 50 to 15G milligrams ofplastic per 100 cc. of treating solution at '70 F. is practical forapplication to pretreated material. Also in the pretreating process thetreating solution should have a lower saturation value than thesaturation value of the solution to be employed in the nal treatment. Ihave found for practical purposes that the saturation value for thepretreating solution should be below 75. Thus where an untreatedfabrication was employed, solutions having saturation values of over 100require considerably more care in technic than where a treatedfabrication was employed with solutions having the same saturationvalue. Also, in practical casts I have employed in the pretreatingmethod, a treating solution having a saturation value of 10 milligramsof plastic per 100 cc. of treating solution and when such plasticpretreated cast material was finally treated in the cast-formingoperation, it was found that a solution having a saturation value of 70milligrams of plastic per 100 cc. of treating solution was highlypractical.

I have further found that where a plastic f abrication is pretreatedwith a solution having a rather low saturation value, the loops in theweave are sufficiently self-sustaining so that the tendency of thematerial to run is substantially decreased. This feature of my inventionhas great utility in the cast eld and also has great utility in otherfields, such as in the treatment of womens stockings or hosiery made ofa soluble plastic. The mild or light pretreatment does not too adverselyeffect a harshness of the material and at the same time it providessufficient loop retaining characteristics so that there results apractically run-proof product. The mild treating solution to be thusemployed should have a saturation value in the neighborhood of lmilligrams per 100 cc. of treating solution at 70 F. As the strength ofsolubility of the treating solution increases it increases the harshnessof the material so that the treating solution, for practical purposesshould be the lowest treating solution which will provide the desiredrun-proof characteristic.

It is interesting to Vnote the very small total weight of the castmaterial which normally will be dissolved by the treating solutions ofthis invention. A considerable excess of treating solution for a givencast was applied and the capacity of such solution to dissolve theplastic involved was determined. It was found that the weight dissolvedwas less than one-half of one percent by weight which again illustratesthe low saturation values here involved.

In the event that the plastic material employed isother than celluloseacetate, obviously those skilled in the art can readily ascertain atreating solution for the plastic material employed and provide the samewith a saturation value in accordance with the foregoing teachings tothereby obtain the benefit of my invention and employ various plasticmaterials.

Application of plastic fabric In the event that the invention isemployed in providing a cast or splint, preferably the skin area to becontacted by the cast shall be covered with a material inert to thetreating solution, such as stockinette, sheet wadding, felt or rayonbandage. In the event that it is desired to `apply the cast directlyadjacent the skin of a patient, the comfort of the patient will beenhanced by shaving off any hair and applying a greasy coating as aviscous mineral oil.

Over the skin or over the padding layer, the plastic material in stripor bandage form is wrapped. In many cases it may be desired to wrap morethan one layer from the strips being employed and in many cases it maybe desired to wrap one layer with the joints lapping at approximatelythe center of the bandage and then to apply a second layer where thejoints between adjacent edges are butted or a second layer in the formof a tubular member. In the event that the cast is to be formed of twolayers it is preferable to apply the rst plastic layer wetted withtreating solution and the second plastic layer dry. However, eitherlayer may be applied wet or dry. I have found very desirable results maybe obtained if the first layer comprises a plastic fabricationpretreated in accordance with the before mentioned method and then aftersaid layer has substantially set to apply a second plastic layer ofnon-pretreated material-for appearance this may be a tubular member tothus provide a continuous exposed surface. By applying an outernon-pretreated layer it tends to shrink onto the first layer and unifythe cast and at the same time the under layer of pretreated materialwill not shrink upon setting because of the pretreating method and thusI have a well conforming and unified cast.

Referring to Figs. 6 and '7 of the drawingsfl I6 indicates theinert'padding material, H1 indicates the first layer wherein adjacentportions are provided with lap joints, and H3 indicates the outer layerwherein the joints are preferably butted.

Referring to Figs. 8 and 9 of the drawings H6 again represents inertpadding material, l Il again indicates the rst layer and 32 representsthe outside stockinette or tubular layer formed of one piece.

In applying the treating solution to the plastic fabrication, thefabrication may be wetted with treating solution before it is applied orelse the plastic fabrication may be applied and then the same wetted. Inorder to apply the treating solution to the plastic fabrication, theplastic fabrication may be immersed in treating solution or the treatingsolution may be poured on, applied by a syringe or spray gun, 0r appliedby a brush to wet the plastic fabrication. A very practical Way ofapplying treating solution to a plastic fabrication, however, is by asyringe emitting a small stream or spray of treating solution. Also, ifthe plastic fabrication is to be immersed in the treating solution avery practical method is by the device shown in Fig. 14 of the drawings.

In said Fig. 14, H9 represents a container to provide therein a chamberE29. A split cover` member |2I has its end portions hinged :byhingemeans .|21 to the .container H9.. Intermediate .the twopieces formingthe .cover member 1| 21| tis provided an Vcperring through which a rod|22 may be slidingly moved. Preferably a catch means |28 is hingedlysupported on the :cover member.j|;2:| `by pivot means |29 and a springmeans t3@ angularly .movesthe catch :means dit into engaging relationvwith .a .rod |22.. .Thus if the rod |22 is moved upwardly it is onlynecessary to hold the cover .means '|21 y:downwardly and afterthe rod|22 .is positioned .in its sclesired upper position it will :be heldsuch vupper 'posi- `tion by .reason Lof the ycatch .means 112i?..n.,reservoir |23 Vtor treating solution l.is provided :and saidreservoir |23 communicates with the :chamber |28 via port |24. A screw:cap 1:25 is .provided to function .as a llilling .means and also as ameans 'to seal the reservoir 123. The :size :of the port V|2 is suchthatthe treating solution inthe reservoir E23 will .be delivered :into 'the`clra-rnber 12.!! in a rather small stream and at .thesame time theliquid level in the .chamber |52!) will 'be up tothe level of the port|24. A tray-.like member |31 is provided 0n which a .roll .of plasticfabrication |26 may be disposed.

In the operation of the'deviceshown in Fir-g. 14 a roll of lplastic.fabrication is .disposed about the rod |22 and on the tray 13|. Thenthe cover means 1.2i yis .opened and the tray I3-l withL the fabrication`|213 thereon is lowered into vthe Acham-- ber |20 and below the liquidlevel ofthe treating solution in said chamber |29. After the plasticfabrication |2'b` :has been thoroughly wetted v4then the 'rod .|22 ismoved upwardly .and .byreasonof the catch means .|28 it lis .retained ata level above the liquid solution in the chamber 1.28. Thus 4in anoperating .room the fabrica-tion :L25 Awill be maintained in a closedcontainer. Also at the same time, in view .of the tpreferable 'volatilena.- ture of the `treating -solutionin the chamber 12d., fumes of saidtreating solution will be presen-t so that a wetted fabrica-tion may:befmaintained in a wetted condition and in the absence -o-f dry-ingconditions so that it will -tbe readily available .so l that as thephysician needs further wetted fabrrcation in applying |a cast therexwill :also be a supply readily available for him.

While it is possible to :provide an .open -cen tainer of `treatingAsolution and to immerse the fabrication .|26 therein such procedure .isnot -desirable and at the same timethe 'volatile treating solution willbe evaporating and .thus .a device embodying the .struc-ture 4of y.sa-idFig. 14 provesto be very practical. It can be 'readily understood that,it requires a mere movement of the :rod .|22 upwardly to remove thefabrication AI 26 Vfrom the treating solution and at the .same time-when the fabrication is, first placed y"ont-he tray 43| that as thecover means close, Athe fabrication `may .be'at once immersed in thesolution in the :chamber 52() or the fabrication may be maintained .at.la level Vabove the solution by .reason of the catch means |28 andthereafter vimmersed vas :and when desired by the physician.

When 'a plastic fabrication lis immersed in a treating solution `of vmyinvention, I have found that some of the treating solutions .tend to beselectively exhausted as to one or more of the components of 'thetreating :solution :and therefore it is desired to periodically `replacethe treating solution into which the fabrication :is 'to 'be immersed sothat the lsaturation value of the treating solution maybe maintained:within .the desired range.

lill

' 'In the event 2that the ,liquid .draining .from Lan immersed:fabrication is .notperm'itted to deposit inthe treating solution, thenof course it will :not be desirable to periodically .replace thetreating solution.

In vthe event that a cast is to be :applied over surfaces, .such as bonyprominences or sore spots, it .may vbe `desired to provide `a padding at:such locations fand this .may be readily accomplished in my invention.Referring to Fig. 10, a padding material |33 such as cellulose acetatestaple, or sheet wadding., orsoftglass wool is disposedfadjacent thelocal area and the ca-st material formed thereover .so that the desiredpadding structure is present. In the event that the padding materialemployed is a cellulose acetate staple, 'the outer portions will beadhered to the cast .and the inner portions will remain untreated inview of the resistance to wetting or being penetrated by a liquid of thecellulose acetate staple. In said Fig. 10 `the balance of the cast mayfollow the .structures of either Figs. 6 and 7 or Figs. Bland 9.

'In the event that -it is desired vto provide zexpansion joints or local`areas in the cast Winch are Y'not to be set-up, vthis may beaccomplished by employing a ,material which will not be affected by thetreating solution, will ynot be washed 01T or dissolved by the treatingsolution, and one which will envelope .or encase a portion of the.fabrication so that such fabrication in such area cannot be affected bythe treating solution. As an example of such a substance which may beemployed with the .fabrication .and the treating solution of this'invention a thin jelly-like solution of gelatin and `water maybeemployed. Furthermore, such jelly material Vma'ybe'vvashed or brushedout after the loastihas been .set-up and then upon removal of the jelly,the portion of the cast which was protected by the jellymaybe subjectedto a treating solution and such portions then set-up.

Referring particularly to Figs. 8 and 9, |34 represents areas `whichhave been protected 'so that the same vhave not set-up and may provideexpansion joints. The .method to be employed in providing non-set-upportions of .a cast is -rnore fully disclosed .in my copendinglapplication Serial No. 4695843, the difference jin Ythe presentinstance being in .the nature of :the fabrication., thetreatingsolution, and the coating material.

.Another feature `of my invention .relates to the cutting of a cast .so.that `.the .cast `may :be removed, repaired, or adj-usted. In Ttheprior lart of plaster of Paris casts, the task vof .severing the cast.in .many cases., as a body cast, was such `a strenuous and tedious taskthat it .has been termed a hammer .and chisel job. `As .distinguishedtherefrom, in `my vcast the same may Fbe chemically or mechanicallysevered or a combination of the two may he .utilized .and at .the sametime with a minimum of effort. Preferably an inert absorbent material,as vsheet wadding,is applied over the area (local or for the length ofthe cast) on which the cut 'is to be made. Then acetone lis sprayed orapplied to the sheet wadding. The sheetwadding functions to provideacetone in `the 'desired area or region and at the same time the acetonecan .function `as a dissolving agent of the cast. 'The cast which has"been so treated `has vbeen found to be readily severable .so that itisronly necessary to use ordinary bandage shears Aand the cast may besevered or local areas removed as may l'be desired. 'Thu-s I have beenable to supplant the old process which was involved in plaster of Pariscasts and which was a hammer and chisel task to a procedure wherein thecast may be severed by mere bandage shears. Even if the acetone isnotapplied to provide the dissolving action above described, it has beenfound that the cast may be severed with greater ease and with lessdifficulty than was required with the old plaster of Paris cast.

Referring to Fig. 11 of the drawings a completed cast is illustrated ashaving disposed thereon sheet wadding |36. Thereafter the sheet wadding|36 is wetted with acetone and a desired local area of the cast |35 isso dissolved or softened that it may be readily removed or reshaped.Preferably the material will merely be reshaped, as an opening may causewindow edema. I-Iowever, if an opening is provided, then as shown inFig. l2 of the drawings, the material |31, which may be similar tomaterial |36 of Fig. 1l, is preferably disposed in the opening providedin the cast |35 and cast-forming material |33 may be applied and thesame may be adhered to and form an integral part of the cast |35. Thus,in the event of sore spots developing under a cast, portions of thedesired shape of the cast may be softened, reshaped, retted, or removed,the pressure removed and the cast repaired to original strength. Thelack of such characteristics has been one of the major shortcomings ofplaster of Paris casts.

VAfter a cast involving my invention has been severed, it may be readilyrepaired and then a coating material embodying the fabrication of myinvention may be applied and then upon the application of furthertreating solution, the patch or repair material will be firmly adheredto the cast and the cast will have its original strength. In the pastwhere plaster of Paris casts were employed, the strength of the castdepended upon the maintaining of its original structural form and anyrepair caused a weakening of the cast unless the repair Work insubstance involved the making of a new cast.

Referring to Fig. 13 of the drawings, a fragment of a cast |39 isillustrated and padding |40 similar to padding |36 of Fig. 11 is shown.Thus in the event that it is desired to provide slits in a cast toremove the cast or to adjust the cast for size, it is only necessary toprovide the material |40 to form a strip and then acetone may be appliedto the material |40 to dissolve the cast. Thereafter by bandage shearsthe cast may be severed for removal or adjustment. If the cast issevered for adjustment then a strip of bandage material may be appliedsimilarly to the description in connection with Fig. 12, and the castrepaired after the adjustment has been made.

This invention accomplishes the Various objects which were set forth inthe first part hereof and provides further results which have been setforth in the description of the various structures and methods. It isbelieved the same are therefoi'e sufficient without further settingforth the same at this place.

Obviously, changes may be made in `the forms, dimensions, andarrangements of the parts of my invention, without departing from theprinciples thereof, the above setting forth only pre-A ferred forms ofembodiment.

I claim:

1. A substantially unyielding and inelastic orthopedic brace comprisinga fabrication formed of plastic fibers thoroughly wetted by a volatileorganic setting agent and thereafter set, the setting agent beingcharacterized by having a saturation value for the plastic of betweenfifty milligrams and three hundred milligrams per one hundred cubiccentimeters of setting agent at 7 0 F.

2. A substantially unyielding and inelastic orthopedic brace comprisingan open mesh fabrication incorporating therein pieces of reinforcingmaterial insoluble in the volatile organic setting agent to be used,said fabrication being thoroughly wetted by a volatile organic settingagent and thereafter set, the setting agent being characterized byhaving a saturation value for the plastic of between fifty milligramsand three hundred milligrams per one hundred cubic centimeters ofsetting agent at F.

3. A substantially unyielding and inelastic orthopedic brace comprisinga pre-shrunk fabrication'formed of plastic fibers which is soluble in avolatile organic setting agent, the said preshrunk fabrication beingthereafter thoroughly wetted by a volatile organic setting agent andthereafter set, the setting agent being characterized by having asaturation Value for the plastic of between fifty milligrams and threehundred milligrams per one hundred cubic centimeters of setting agent at70 F.

4. A substantially unyielding and inelastic orthopedic brace comprisinga pre-shrunk fabrication formed of plastic fibers which is soluble in aVolatile organic setting agent, the setting agent being characterized byhaving a saturation value of less than seventy-five milligrams per onehundred cubic centimeters of solvent at 70 F., the said pre-shrunkfabrication being thereafter thoroughly wetted by a volatile organicsetting agent in which the same is soluble, the setting agent beingcharacterized by having a predetermined saturation limit for saidplastic to gelatinize and dissolve part thereof without destroying thestructure of the fabric.

5. A substantially unyielding and inelastic orthopedic brace comprisinga pre-shrunk fabrication formed of plastic fibers in a volatile organicsetting agent and which has been preshrunk by heated uid at atemperature of between 350 F. and 425 F., the said pre-shrunkfabrication being thereafter thoroughly wetted by a volatile organicsetting agent in which the same is soluble and thereafter set, .thesetting agent being characterized by having a predetermined saturationlimit for the plastic to gelatinize and dissolve part thereof withoutdestroying the structure of the fabrication.

6. A substantially unyielding and inelastic orthopedic brace comprisinga fabrication formed of plastic fibers thoroughly wetted by a volatileorganic setting agent and thereafter set, the setting agent beingcharacterized by having a saturation value for the plastic of betweenthree hundred milligrams and one hundred fifty milligrams per onehundred cubic centimeters of setting agent at 7 0 F.

7. A substantially unyielding and inelastic orthopedic brace comprisinga fabrication formed of cellulose acetate fibers thoroughly wetted by avolatile organic setting agent and thereafter set, the setting agentincluding therein acetone and a diluent which is a non-solvent forcellulose acetate, the setting agent being character- 17 n 18 ized byhaving a saturation value for the plastic UNITED STATES PATENTS ofbetween fifty milligrams and three hundred Number Name Date milligramsper one hundred cubic centimeters of 696,123 Weidig Mar. 25, 1902 Settmgagent 70F- 2,219,829 Teague @qu 29, 1940 ROGER ANDERSON. 5 2,292,531Lovell Aug. 11, 1942 OTHER REFERENCES REFERENCES CITED IndustrialSolvents by Ibert Mellan, published The following references are ofrecord in the by the Remhold Pubhshmg Corp of New York' l l0 New York.Copyrighted in 1939. Pages 47 and le of this patent. 52. Copy mmv. 64.

